A capacitor is an indispensable component for electronic equipment which serves as a decoupling capacitor for suppressing noise generated by such electronic equipment, a coupling capacitor for eliminating the difference in d.c. potential between electronic devices, a component of a filter, or the like. With recent downsizing of electronic equipment, downsizing of such a capacitor has been requested.
Capacitors suitable for downsizing include a ceramic capacitor and an aluminum electrolytic capacitor. These capacitors have a high capacitance per unit volume and hence can maintain a relatively high capacitance even when downsized.
Japanese Patent Laid-Open No. HEIS-47589 discloses a ceramic capacitor which ensures a required capacitance by forming a dielectric layer from a ferroelectric material such as barium titanate. A stacked ceramic capacitor, which has a further increased capacitance than the ceramic capacitor, includes alternately stacked electrodes and dielectric layers. The aluminum electrolytic capacitor realizes an increased capacitance by expanding the surface area of an anode foil by making the anode foil surface rough.
In order for such a conventional capacitor to have a high capacitance, a complicated and precise fabrication process is necessary. Therefore, the fabrication cost increases in order to impart such a capacitor with a high capacitance.